• 농촌계획
• /
• 제22권3호
• /
• pp.21-31
• /
• 2016

This is a comparative study focused on the scenic landscape preferences derived from visitors's perceptions at the Dulle-gil and the uphill trail in Bukhansan National Park. Unlike previous landscape assessment methods, this study contains more direct and on-site analysis with methods of understanding the visitors' perceptions by using 'visitor employed photography(VEP)' which requires each visitor to take preferable scenic landscape with one's own smart phone camera. The scenic landscape types at two different trails were categorized and then the types favoring most of participants were verified. There are total number of 16 visual landscape types preferred by participants at both the Dulle-gil and the uphill trail in Bukhansan National Park. As in terms of consensus photography(CP) on the Dulle-gil was found to have more diverse elements including both natural and artificial elements compare to the uphill trail. Furthermore, the perceptually excited node(PEN) at the Dulle-gill were found to be more scattered evenly whereas PEN at the uphill trail were concentrated on the entrance and the top of the mountain. It is necessary to consider that the scenic landscape management at the Dulle-gil and the uphill trail require different approaches. Facilities were set based on careful consideration of distinctive geographical features and vegetation in the Dulle-gil. And the management need to be focus on the 'forested area' maintaining natural state in the uphill trail. Futhermore, the result of the CP and PEN in the trails would be helpful to proceed the next step of landscape perception study depending on characteristics of groups.

• 한국산학기술학회논문지
• /
• 제7권2호
• /
• pp.97-100
• /
• 2006

연강에서의 동적인 크랙 전파는 충격 하중을 받는 3점 굽힘 시험편들에 의해서 연구되어진다. 시험편은 10mm의 두께를 가진 $320{\times}75\;mm$의 크기를 가지고 있다. 하나의 정적인 실험과 30.2 m/s 및 45.2 m/s의 충격 속도들을 가진 두 개의 동적 실험들이 행하여진다. 고속 카메라는 크랙 성장과 크랙 선단 개구 변위들의 데이터를 얻는데 사용되어진다. 두 개의 반쪽 시험편들의 상대 회전을 직접 측정하기 위해서 Moire의 간섭 패턴을 사용한다. 실험들에서는 크랙 전파에 대한 하중 속도의 영향이 없거나 약간의 영향이 있는 것으로 나타나고 있다.

• International Journal of Automotive Technology
• /
• 제2권3호
• /
• pp.85-91
• /
• 2001

Characteristics of methane direct-injection spark-ignition stratified combustion in lean hydrogen mixture were analyzed both in a single cylinder engine and in a constant volume combustion chamber. Combustion pressure and Instantaneous combustion chamber wall temperature during the combustion process were measured with a thin-film thermocouple and used in analyses of combustion and cooling loss. Results in this research show that the premixed hydrogen increases cooling loss to combustion chamber wall while achieving combustion promotion, and the combustion system is effective especially in lean mixture conditions. Analysis of flame propagation was also done with Schlieren photography in the constant volume combustion chamber.

• 대한기계학회논문집
• /
• 제16권5호
• /
• pp.933-942
• /
• 1992

본 연구에서는 이상류 동축 노즐의 미립화 기구를 규명하기 위한 기초단계로 20˚의 증류수를 사용하여 이상류 동축노즐의 평균액적 직경에 미치는 공급유량의 영 향을 직접사진 촬영법을 사용하여 규명하고자 한다.

• 한국언론정보학보
• /
• 제71권
• /
• pp.75-115
• /
• 2015

이 글은 $5{\cdot}18$ 관련 초상사진을 보면서 떠오른 연상들의 의미를 현상학적으로 기술한 것이다. 사진의 지시 대상은 각각 다르면서도 특이한 유형의 연상들을 불러일으킨다. 그리고 그 연상들에 따른 감정 체험도 다르게 나타난다. 따라서 이 연구의 목적은 $5{\cdot}18$ 초상사진들을 통해서 마주친 지시 대상에 대한 연상의 유형과 그 감정 체험을 기술하고, 그 의미를 구성한 것이다. 현상학에서 말하는 연상 개념들에 근거하고 있지만, 이 글에서는 연구자가 사진을 통해 직접 체험한 연상의 의미에 중점을 두어 $5{\cdot}18$민중항쟁에 대한 역사적 의미를 기술했다. 연구결과로 $5{\cdot}18$민중항쟁의 관점은 객관적인 학문 체계나 정치적인 이데올로기의 역학관계로 단순히 환수시켜 버릴 수 없다는 것이다. 그것은 항쟁에 참여한 개별자들마다의 근원적이고 충동적인 연민이 작용했고, $5{\cdot}18$민중항쟁의 근원은 이미 그들의 삶의 토대와 사랑의 공동체로서 힘의 의지에 있었다는 것이다.

• 한국자동차공학회논문집
• /
• 제8권3호
• /
• pp.28-36
• /
• 2000

Spray characteristics of diesel fuel injection is one of the most important factors in diesel combustion and pollutant emissions especially in HSDI (High Speed Direct Injection) diesel engines where the interval between the onset of combustion and the evaporation of atomized fuel is relatively short, An investigation into various spray characteristics from different holes of VCO(Valve Covered Orifice) nozzles was performed and its results were compared to standard sac nozzle. The global characteristics of spray, including spray angle, spray tip penetration, and spray pattern were measured from the spray images which were frozen by an instantaneous photography with a spark light source. For better understanding of spray behavior, SMD of the fuel sprays from multi hole nozzles were measured with back light imaging while the sprays from the other holes are covered by a purpose-built nozzle cap. The investigation manifestly reveals the different spray patterns at the beginning of injection produced by VCO nozzles can be identified as three distinct types with their own macroscopic and microscopic characteristics, while macroscopic non-uniformity disappears at 0.9∼1.0ms from the start of injection.

• 대한기계학회논문집B
• /
• 제30권5호
• /
• pp.413-421
• /
• 2006

The bubble dynamics induced by direct laser heating is experimentally analyzed as a first step to assess the technical feasibility of laser-based ink-jet technology. To understand the interaction between laser light and ink, the absorption spectrum is measured for various ink colors and concentrations. The hydrodynamics of laser-generated bubbles is examined by the laser-flash photography. When an Ar ion laser pulse (wavelength 488 nm) with an output power up to 600 mW is incident on the ink solution through a transparent window, a hemispherical bubble with a diameter up to ${\sim}100{\mu}m$ can be formed with a lifetime in a few tens of microsecond depending on the laser power and the focal-spot size. Parametric study has been performed to reveal the effect of laser pulse width, output power, ink concentration, and color on the bubble dynamics. The results show that the bubble generated by a laser pulse is largely similar to that produced by a thin-film heater. Consequently, the present work demonstrates the feasibility of developing a laser-actuated droplet generation mechanism for applications in ink-jet print heads. Furthermore, the results of this work indicate that the droplet generation frequency is likely to be further increased by optimizing the process parameters.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회B
• /
• pp.3329-3334
• /
• 2007

The purpose of the research is to investigate of diesel spray combustion for simultaneously reduce way NOx and PM. The pressure diesel injection were done into intermediates that are generated by very lean DME HCCI combustion using a RCM. The concentration of intermediate could not be directly measured; we estimated it by CHEMKIN calculation. DME HCCI characteristic is surveyed. Validations of the CHEMKIN calculation were confirmed pressure rise of an experiment and pressure rise of a calculation. Using a framing streak camera captured two dimensional spontaneous luminescence images from chemical species at low temperature reaction(LTR) and high temperature reaction (HTR). Also, the combustion events were observed by high-speed direct photography, the ignition and combustion were analyzed by the combustion chamber pressure profiles.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집D
• /
• pp.871-877
• /
• 2001

Experimental study was conducted to investigate the effects of axial forcing on the flame structures near the nozzle exit of non-premixed flame. The most notable observation is that the direction of vortical motions is changed at some ranges, according to the increase of excitation amplitude. Especially, the elongation flame and the phenomenon of In-burning are always occurred when the vortical motion turnabout. In an analysis of the flame/flow visualization by means of direct photography and RMS technique, a plausible explanation can be made that above phenomena are related only to the amplitude of phase average velocity between the instantaneous velocity elements of excited flow.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.1134-1139
• /
• 2004

Recently, development of flame control scheme has been hot issues in the combustion engineering. It has been held that flame shape can be controllable by pressure inside combustor. The influence of combustor atmospheric pressure on flame shape was investigated in the present study. The flame shape, flammable limit, flame temperature and nitric oxide emission were measured as functions of combustor atmospheric pressure and equivalence ratio. The reaction region became longer and wider with decreasing combustor atmospheric pressure by direct photography, hence reduction of blow off limit. This tendency was also observed in the mean flame temperature distribution. Nitric oxide emission decreased with decreasing combustor atmospheric pressure. Low NOx combustion is ascribed to wide-spread reaction region in the low atmospheric pressure condition. These results demonstrate that flame shape and nitric oxide emission can be controllable with combustor atmospheric pressure.